Effectiveness and Safety of the COVID-19 Vaccine in Patients With Rheumatoid Arthritis in a Real-World Setting

Background: To describe the effectiveness and safety of COVID-19 vaccine in a series of patients with rheumatoid arthritis (RA). Methods: Retrospective single-center study of RA patients, fulfilling the ACR 1987 or ACR/EULAR 2010 classification criteria, that received first COVID-19 vaccine between December 2020 and October 2021, had post-vaccination serology and subsequent follow-up of at least 6 months in a university hospital. Vaccine effectiveness was evaluated by the serological response and the incidence of post-vaccine COVID-19, and safety by the incidence of adverse events (AE) and RA flares. Adjusted logistic and linear multivariate regression analyses were carried out with Stata® to identify factors associated with vaccine response. Results: We included 118 patients with RA (87.2% women, age 65.4±11.6 years, evolution 12.0±9.6 years). 95.8% received complete vaccination schedule. Most patients (88.1%) developed adequate humoral immunogenicity, and the degree of serological response was significantly related to younger age and previous COVID-19 infection. After vaccination, 18.6% presented mild SARS-CoV-2 infection. Vaccine AE (19.5%) were mostly mild and inversely associated with age (OR 0.95). RA flares were anecdotal (1.7%) and inversely related to age (OR 0.95). Conclusion: Our results suggest that COVID-19 vaccine induces adequate humoral immunogenicity, with an acceptable safety profile in RA patients.